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Bond lengths in platinum(II) and platinum(IV) complexes. Crystal and molecular structure of cis -tetrachlorobis(triethylphosphine) platinum(IV)
397
Joumd
of Organometallic
Q Ekevier Sequoia S.A,
BOI’IZ) LENGTHS And
I-“: PLATINUM(U)
BIOLECUIAR
PHOSPHIKE)
PETER
AKD
STRUCTURE
PLATINUM(W)
COMPLEXES.
CRYSTAL
OF -cis-TETRACHLOROBIS(TRIETHYL-
PLATINUM(lV)*
B.
HITCI-ICOCK.
School of Molecular
(Received
Chmkizy, 136 (1977) 397-406 Lausenne --Printed in The Netherlands
BARBAR
Sciences,
May 3Ist.
JACOBSON.
University
AND
of Sussex.
A WN
PIDCOCK
Brighton
BNl
9QJ
1977)
SUMRIARY
The crystal determined. 12.5GlQ).
Crystals c=
are
The crystal
Steric
P&P
P).
P-R-P’
SY;l~.* cause
some
Bond lengths
in platinum(W)
and available
results
carbene
in metal-l&and related
~Z/‘~,
m
complexes
depend on the nature
ligand
to PtO-P
frequencies
to the changes
octahedral
between
llgands
(L
co-ordination. &and,
orders:
to Pt(Iv)-Cl
lengths).
to
of symmetry
of the trans
the trams influence
(with respect
by
to C1) and 2.394(3)
the phosphine
from
used to determine
regular
b =
measured
with a C, axis
2.32l(3) between
were
atom method and refined
molecules
Pt-Cl
has been
a = 8.791(2),
Intensities
deviations
(with respect vibrational
discrete
principally
~phosphineccarbonionic
c
simply
are
group = 4.
by the heavy
2.335(3).
interactions,
(ato
space
solved
comprises
with bond leng?ths (in 1)
of c&-[PtC14(PEt3)21
p = 91.92(2)*. z
and the structure
= 0.053.
structure
monoclinic,
17.899(3)J(.
diffractometer g
and molecular
Cl<<
lengths)
and Cl
It is shown that differences
platinum(W)
complexes
are
not
in the bond lengths.
INTRODUCTION
The oxidative reactions
and reductive
that are homogeneously
the interconversion RhI or RB) R-
addition
No reprints
of square
and octahedral available
catalysed
planar
complexes
elimination by transition
complexes of higher
of lower oxidation
cycles metal
of several complexes
oxidation states
involve
states (such as III or PtIv). In
(Rh
398 recent years accurate planar
complexes,
especially
such as platinum(W) scopic
evidence
the tnns bonds
suggests
report
those of platinum(iI).
structural strengths
may be substantially
the crystal
provide
for platinum(R)
and platinum(W)
is spectro-
on the nature
to that of platinum(R)-l&and
bonds
complexes (as indicated
of &-[PtC&(PEtJd;
complexes
by the We now
the bond lengths
points of comparison
from
of
with resuks
the literature.
PtCI,(PEtJ,]
-,i-ere obtained with chlorine
by treatment
of&-[ptCl,-
followed
by recrystallisation
a = 8.791(2).
2 = 12.501(2).
dichloromethane-ether. Data
17.599(3) C-X-~,
ii,
I,
e = 91.92(2)‘.
F(000)
= 1112.
systematic
573.3,
radiation,
of h&l
for
A crystal
di&actometer
calculated
of size
&aphite a triclinic
from
on a Hilger
cell and accurate
the setting
angles
X=
and it was
space
g
groups2/c
91.13O.
Intensity
by an L‘ /2 6 step scan. two-fold
symmetry
found that the crystal
Preliminary
photographic
data were
= 0.70926_:]
2 = 7.638(2)
data for unique reflections After
the structure
-1,
on
e-t = 70.23
n-ith 2~6~
had been solved.
a re-examination
axis was
the needle
circle
in this assignment
[ .I (JIo-_K1)
h = 7.644(l).
prompted
needle
.
along
Y2SO four
ceR dimensions
of 12 reflections
(2).
$ = 85.92(2),
and Watts
monochromator)
crystal
to give a = 17.599(3).
high molecular
cm-l,
DC = 1.S4
@ f C, odd and & 0 1 for 1 odd.
O.&T x 0.36 x 0.18 mm u-as mounted
the diffractometer
collected
w = S1.S
2 =
Measurements
and used for data collection
had indicated
JIonoclinic,
U = 1965.9_i_3. Z = 1, Dm=2.17(flotation).
MO-Iipc
absences
Crystallorrraphic
were
states
in these two o_xidation states.
a nurmber of significant
of c&-[
C+&I,P,R,
axis
depend
there
for platinum(N)
and Pt-Cl
structure
in benzene-dichlo_romethane
Crystal
from
similar
Whilst
oxidation
I\;TA L
Crystals
from
of Pt-P different
and molecular
in this compiex
(X%3)2]
bond str’engths
information
for many square
but the higher
neglected,
in a way that is qualitatively
that the relative
E XPER’IME
has been obtained
have been comparatively
the available
bond le&hs)
information
that platinuxn@W-Ii,-
ligand
[l].
structural
the
of the unit cell.
in fact a face diagonal
25’
of the
399 monoclinic cell shown in the crystal data.
The intensity data u-as re-indexed on the
basis of the monoclinic cell using the matrix (0 Lore&z
-1
l/O
1
l/l
0
0).
and polarization corrections were applied and the data corrected for
absorption with the program ABSCOR[2].
Symmetry equivalent reflections were
averaged to give 1653 independent reflections with J_ >
30 0.
Structure Determination All non-hq-drogen atoms were kxated by heavy atom procedures with the molecule lying on the crystaIIo,mphic
two fold axis.
Least squares refinement =
with anisotropic temperature factors converged at & TABLZ
Pt CUl) CI(2) P(l) C(l) C(2) C(3) C(4) C(5) C(6) H(l1) H(12)
HCZU
H (22) H (23) H(31) H(32) HMU H (42) H (43) H(51) H(52) H(61) H(62) H (63)
Hydrogen atoms
1
FRA cTIOX4 L ATOMIk
Atom
0.058.
CO-ORDINATES
X
0 2-105(3) -816(4) 699(3) -584(14) -296(1S) 25S3(13) 3897(14) 7570 6) -729(19) -50208 -1726(14) -11 SO(19) -565(1 S) 769(19i 2750(13) 2666(13) 5091(14) 3718(14J 3532(14) 1515(16) 1220(16) -61’7(lS) -1458(19) -1222(19)
(x10”) WITH STANDARD
Y
1039.5(4)
1005(2) -356(2) 2264(2) 3395(S) 4153(11) 2804(S) 2077(12) 1720(10) 1352(13) 3847(19) 3086(S) 4724(11) 3713(1X) 4571(11) 2959(S) 3547(S) 2206(12) 2016(12) 1345(12) 1040(10) 2332(10) 91903) 2037(13) 8340 3)
DEVIATIOI’G
z
2500 3076(Z) 3311(2) 1588121 1495(7) 857(S) 1750(7) 1508(g) 648(6) 284(S) 2009(7) 1417(7) 956(S) 351(9) 80i (9) 2341(7) 1445(7) 1639(S) 910(S)
1769(S) 669(G) 296(6) -233(S) 189(S) 694(S)
400 were
introduced
fined as rigid methylene atom,
at Mealised
bodies
positions
with a common
hydrogen
atoms were
again with a common
at 3 0.053.
Scattering
Fo?, . from
3.
ref.
thermal
FinSi
ARD
are
1.
regular
P(l’),
Cl(2).
distances
octahedral and Cl(2’)
from
smaller angle
structure
and angles
above 0.060~
from
and is enhwged
hydrogen
atoms
obtained
2.4721 and the van der
from
(90.24
C(6’)
[H(6’3’)]
appears
given
+ 0.000025 were
taken
1, and anisotropic
Waals
scheme
to be free
for the atoms
lies between
(P) and 0.036_:
is given
some
and below
P(1’)
which
are
above
90’ due to H..
co-ordinates
some-xhat [;t] _ The
from
(2. SOi).
(177.84. because
atoms
RC12-
.H contacts
between
distances
atoms,
are
and some
the bond angles
compression
in -cis-[
of the hydrogen
P(l),
and Cl(2’);
Several
ligands.
contact distance
these tu-o chlorine
angle
in
by Pt.
found for c&-[PtC1,(PJIeJz]
to the corresponding
of
distortions
plane defined
(Cl).
and Cl(l)-Pt-CI(1’) from
3. and a diagram
and shows
P(1) and C1(2),
is evidellt
(86.59.
by nor-ma1 van der
in Table
A least-squares
from
the ideallised
of the l%Cl, moiety
Cl(Z)-Pt-Ci(2’t
are
of the triethylphosphine
between
Cl(2)
corrections
units separated
planarity
: simibr ..s
Ii . . . Cl,
(88.2’).
parameters
and dispersion
OF discrete
passes
(98.14
[96.2(4)4
compression
converged
2.
co-ordination.
than the deviations
methylene
for positional
and
carbon
Refinement
as 3 = 102/(l
has a C, axis of symmetry
the plane are
P(l)-pt-P(1’)
(PJIegJ
re-
factor,
empirically
with the numbering
The molecule
from
factor.
are given in Table *
in Table
composed
Eond lengths
contacts.
Figure
atoms
co-ordinates
given
temperature
were
on the corresponding
shift to error
u-as defined
groups
DISCUSSION
The crystab
the molecular
are
Methyl
isotropic to ride
temperature
for neutral
atomic
parameters
RESI_%TS
Wials
hydrogen
isotropic
scheme
factors
1 .OS A].
constrained
EL = 0.070 with a maximum
The weighting
of 0.08.
[d(C-HI
Cl(l)-Pt-Cl@‘)
The angle a hydrogen
Cl(l)-Pt-
atom on
@I.. . Cl distances
2.47 and
2.89-i). The length of the Pt-Cl(l) those
in trans-[PtCl,(PEtdJ
pyridinepIatinum(IV) from
bond trans
[2.332(5!
[mean
value
2.316(11)
that in [RCl,(C&,Nl,C$IJ[mean
* Structural
factor
tables
are available
to chlorine
[2.321(3)
&s
A] 151 and tetrachloro(pyridinium
value
from
A] [S],
and is not significantly
2.290(16)f\]
[7J.
similar
to
propylide) different
The bond lengths
in
the authors, (Continued
on p-403)
401 TABIX
2
ANISOTROPIC U&%
STAhQARD
Atom
PARAMETERS
Pt
341(3) 435(15) 65907) 431(13) 689(70) 853tSSI 499(59) 475(64) 782(81) 964(112)
a(2) P(l) C(1) C(2) C(3) C(4) C(5) C(G)
1,
probability
*2
DE~TIOIXS
A view
-f-
IN
Cl1
cm
Fig.
THERhtiL
* 2 + L’,g_2&.*2 + u&g
2u,g.&9*
(xl0’)
282 (3) 6140 9) 37OU 3)
594(4 856(21) 808(19)
342(13) 612(16) 427(.57) 669(68) 545(701 825(91) 423Es1 836(80) 723(85) 1 OSG(108) 571(68) 494(59) 763(68) 727(86)
of the molecular
_ The molecule
THE
FORM:
+ 2U2&ib*
exp[-2m*CT] WITH
PAREMHESIS
u33
%2
OF
i- 2U, &&a *g’
structure;
hzx a two fold uis
c 12
0 -2(11)
-7G(ll) 22(11) 145(51) 144(6-a -77(4G) 75(60) 4(58) 29(82)
thermal
ui
3
-35(2) -103(14) 80(14) -13(11) Gl(55) 116(731 79(55) -45(65) 17(55) -151(78)
ellipsoids
of symmetry.
enclose
‘23
0 98 (14) 92(12) 28 (10) 132(50) 201(64) 26153) 75 (77) -37(49)_ -251(74)
50$,‘&of
402 TABLE
3
SELECTED
ILNTERATOMIC
STA XDA RD
DISTANCES
(_:,
Ahi
AKGLES
(‘1
W7TH
DE VIA TIOSX
Bond lengths
Pt-Cl(l)
P(l)-C(5) C(l)-C(2) C(3) -C(4) ‘X5)-C(6)
2.321(3) 2.3%(3) 2.335(3) l.Sl3rll)
Pt-CI(2) 5%-P(l) P(l)-C(1)
1.816(11) 1.512(17) 1.536(17) 1.X2(19)
Bond angles P(l)-Pt-P(1’)
98.1(1)
R-P(1)-C(1)
113.4(4)
P(l)-Ft-CI(l)
93.8(l)
Ft-P(l)-C(3)
113.3(4)
P(l)-Pt-CI(l’) P(l)-Pt-CI(2’) Cl(l)-J?t-Cl@! Cl(l;-Pt-C1(2’) C1(2f-Ft-Cl(2’) P(l)-Pt-CI(2) c-(I)-Ft-Cl(1’)
87.6(l) 87. SW
Pt-P(l)-C(S) C(l)-P(l)-C(3)
114.7i-1) 106.8(6)
90.2(l) 88.20) 66.50) 172.90) 177.811)
C(l)-P(l)-cm C(3)-P(l)-C(5) P(l)-C(lt-C(2) P(l)-C(3)-C(4) Po)-C(5)-C(6)
19i.l(6) 103.5(G) 116.0(9) 115.1(9) 117.5(10)
TABLE
4
YEAS
BOXD
LENGTHS
(_%) IN cis
AXD
trans
ISOMERS
OF [PtC12(FXt-J.j
[14C~p=J):l
Configuration
Bond Pt-P(trans
to Cl)
-cis
2.“5wa
Ft-Cl(trans
to P)
-cis
2.361(s)
trans
2.314
trans
2.301m
pt-PW
to P)
Pt-Clkrans
a
ref.
12.
to CO
b this work .
c estimated
pt(IW
PtCrn
values
2.335(3)b 2.394(3)
c’
- see text.
.2.393(5) 2.332(s)
d
ref.
5.
d
A&m
403 the trans
P-Pt-P
moieties
of trana-[PtCl,(PEt$J
(Cl,C~~(~~~Ie)~(PEt~JC10~~rnean so the available are
results
not signifioantly
the Pt-Cl
lignnds
trans
to a carbene
2.415(4)
are
trans
manner: d
ionic ligands
2.362 trans
.
There
results
methyl
containing
(this work
two-dimensional bond lengths complexes.
value
obtained
Pt-Cl
moiety
(PAIeJJ
2.314(81
51, but the results
group.
increase the nature
The
and 2.315(4]
by 0.08i
i
distance and other
distance
complexes is estimated complexes
by 0.03A
@and.
Comparison
that there
are
was
isomers
of the
and [PtCII(PEtJJ were
obtained values for
depend
mainly
at 2.301(5) containing
from
of the
the results
related on the
.$ from
the
a trams Clfrom
the
[14] and trans.-[I%&of platinum(Ib
and the Pt-P not significantly
of bond lengths
states.
group.
accurate
from
in
for these
of 2.31415) _t can be inferred
, and that these increments
of the trans
More
found for trans-[PtBr,(PEtdJ
increase
distances
and piatinum(I0
and trans
(‘Ikblo 4) show that on oxidation
distances
to carban-
the Pt-Cl
(12,141
2,301(4)
to triethyl-
who showed
for trans-[RC12(PEt3)2]
in platinum(B)
Pt-Cl
For are:
tnns
that at least
for both &
[RCl#Et-JJ
[9].
ligands
to the methyl
can be estimated
- [lo]
and the R-P
the Pt-Cl
trans
of low precision.
the bond lengths
[16] _ The results
plstlnumQVl
complexes
for [PtCl$PEt3)] [la.
ligands
and
to tri-
in the h\-0 oxidation [l]
2.372(3)
m
1131 trans
for platinum(IVJ
have been determined
in trans-[PtClz(PEtJJ] since
indicating
et al.
5).
in a similar
lignnd
2.361(S)
between
is similar
of ‘J(Pt-C)
various
data and so are
of the trans
values
values
and platinum(W) and ref.
correlation
on
(this worlr),
vary
to various
[ll],
Both
with thevarious
and 2.393(j)
and 2.398(4)-2.4l5(-1)
to those of Clark
between
Bond lengths
ligand
influence
a good correlation
complexes
and ref.
lengths
to a carbanionic
complexes,
of a
Pt-P
similar,
depend si,tiicautly
to Cl (this work
(in A) traua
is a satisfactory
are analogous
complexes
trans
[12].
closely
relationship.
to triethylphosphine The
to a carbene
and platinum(lB
the mechanism
in &
(this work), 2.388(4)
distances
also
lengths &I A) associated
[a].
i
[5] and of [PtClEC-
in platinum(IV)
complexes
trans
l@nd
to chloride
Pt-Cl
the platinum(IW
nature
2.38-S(3)
A]
IS] are
of ligands
and 2.332(51 trans [S].
in&-[PtCl,(PEtJJ
platinum(B)
P&Cl
18. 5j, and 2.418(3)
to Cl [lo].
These
The
trans
platinum(JI)compl
ligands
ligand.
ligand
2.335(3)
phosphine
in platinum(IW
to a carbanionic
ethylphosphine
trans
on the nature
lengths
2.321(3)
2.388(4)]
that the bond lengths
dependent
of the trans
B
-_
su,qest
and the Pt-P
the nature
value
[2.393(5)
to
distances de_pendent on
in the square
planar
404 rhodium(I)
complex
corn&z
mhCl(PPhJ
B-mhCl,(PBuJ,
the Rh-Cl
platinum similarity
because
ordination
number
contrast
lengths
-[MC14(P31e$h)2] ordination
and 0.029(6)
[&I =. Re, aith
bonds
octahedral
for which
figuration,
a more
complexes
involves
Mason
results
et al __.
to provide
In the platinum
of the M-P
sense
a change of co-
thl?kchanges
there
in M-P and trans
is no variation
me),
N
in CO-
from
0.028(6)
;\I0
(Cs),
to
an&
of these
CI-pt-Cl
Pt-P
complexes,
detailed
analysis
removal
are involved
of electrons
in a graph
quantitative
appears
but the changes
at present.
to be
in the JI-
A number
The oxidation
of (ideallised)
in the oxidation
be a possibility
a more
on oxidation
of un-
of the
tzg symmetrya
of platinum(IQ
to platinum
be&u-een the results
for iridium-
of AI-P
Iength against
of error
in attempting
explanation
electron
con-
to extra_polate
of the bond length
changes
complexes. in Table
complexes.
mean wavenumber
for
d6
The results
to those found for platinum.
4 can be compared
A detailed
has been made for trimethylphosphlne
cm-l
complexes
x-[i\ICl,(PMe,Ph)~
bonds
[5] noted a discontinuity
The bond lengths
for
structure.
by 0.025(3)
for the platinum
precludes
so there would
parameters
involves
They found that on oxidation
state.
to Cl) shorten
(WJ and those for platinum(Iv),
+S cm1
the
to octahedral
who studied
OS, and Ir).
in the opposite
the da2 electrons
ALo,
[a
complexes
The lengthening
A @r).
are
certainties
to platinum(lV)
of Mason&&.
oxidation
Cl lengths
The
li,ds,
noted for the platinum
and M(ll.9
(trans
to that observed
their
to I? is
than that for the
d8 complexes
as a change of electronic
in the M(m)
analogous
0.
state
and the M-P bonds (trans to I?) lengthen by 0.047(6) (Re). 0.040 (OS
A(k),
whereas
oxidation
bond (trans
in the phosphorus
that the trends
p?.atinum(II)
with those
number
the M-Cl
0.037(6)
that in the higher
is less precise
of sq*uare planar
from
as well
somewhat
X-Cl
&I(W)
suggests
rhodiumcm)
_ The oxidation
ard
shows
of the variation
for ox&&ion
in the octahedral
longer and the Rh-P
to p) is 0.03i
of the results
complexes
[181
Although this comparison
complexes
may be general
with those
P(ObIe)J
bond (trans
longer.
0,065~
J [q
changes vibrations,
vibrations
trans
-9 cm-’ to Cl,
study of the platinum-llgandvibrations
analogues
on oxidation
with other_physicaL
of the complexes
from
for
R-Ci
and -9 cm-l
pl&inum(IL) vibrations for
P-Pt-P
in Table
4 [l
to platinum(lVl e
to 9.
vibrations.
Sj . are
-19 The
405
differences
in vibrational
(1W complexes
frequencies
were also studied.
between octahedral
and they appear to correlate
with the bond length changes found by Mason _et al. vibrational simply
frequencies
[S’j .
on oxidation of platinum(IIl
frequencies
valid method of estimating lJ(Pt-P)
relative
for trans.-[ PtCl,(PbIeJd
bond strengths, is
factor
2
platinum(X)
is 0.646 [19].
Since the coupling constants are related
orbitals
forming
ideallised
the I+P
complex,
of 0.664 smaller
corresponding
and the similar
assumptions
involved
complexes
consistent
and the implied
with the observed
platinum(R)
complexes
to be necessarily
are not inconsistent
of the
for the
Although there are
of the coupling for the -cis and
in the changes in the Pt-P bonds are
closely
the smaller
For
between the coupling constants
that bonds with a higher s-orbital
Although the s-components
are now shown to be associated
the Pt-P
than that for the
values of the factors
there is a fair correlation
component are also shorter.
theory,
coupling constant
changes in length of the IX-P bonds (Table 4).
and the I%-P bond lengths [21], which implies
hybridization
may not be a
to the s-characters
in the interpretation
similarity
of
factor for the -cis complexes
states of platinum [20].
constants [ZO]. it is now clear that the similar
not
comparison
bonds, a factor of 0.667 would be expected
dsp2 and d2sp3 hybridization
some significant
expected
are clearly
complexes
The n.m.r_
well
the changes in
to platinum0
in square planar and octahedral
and platinum
reasonably
However,
related to the bond length changes (Table 41. so the direct
vibrational
m
iridium(IlR
of the bonds are not
related to the values obtained from simple coupling constants for the platinum(W)
with relatively
with the possibility
lon,m Pt-P
bonds. and the results
that the correlation
lengths applies to both platinum0
complexes
and platinum(W)
between ‘J(Pt-P)
and
complexes.
A CK-NOWLEDGENEhTS
We thank Professor studentship
R. RIason for X-ray facilities
and S.R. C. for a
(to R-J.!.
REFERENCES
1.
H. C. Clark, 1973.
L.E.
hlanzer,
and J.E .H. Ward,
Canad. J. Chem.,
52 (1974)
Joumd
of Organometallic
Q Ekevier Sequoia S.A,
BOI’IZ) LENGTHS And
I-“: PLATINUM(U)
BIOLECUIAR
PHOSPHIKE)
PETER
AKD
STRUCTURE
PLATINUM(W)
COMPLEXES.
CRYSTAL
OF -cis-TETRACHLOROBIS(TRIETHYL-
PLATINUM(lV)*
B.
HITCI-ICOCK.
School of Molecular
(Received
Chmkizy, 136 (1977) 397-406 Lausenne --Printed in The Netherlands
BARBAR
Sciences,
May 3Ist.
JACOBSON.
University
AND
of Sussex.
A WN
PIDCOCK
Brighton
BNl
9QJ
1977)
SUMRIARY
The crystal determined. 12.5GlQ).
Crystals c=
are
The crystal
Steric
P&P
P).
P-R-P’
SY;l~.* cause
some
Bond lengths
in platinum(W)
and available
results
carbene
in metal-l&and related
~Z/‘~,
m
complexes
depend on the nature
ligand
to PtO-P
frequencies
to the changes
octahedral
between
llgands
(L
co-ordination. &and,
orders:
to Pt(Iv)-Cl
lengths).
to
of symmetry
of the trans
the trams influence
(with respect
by
to C1) and 2.394(3)
the phosphine
from
used to determine
regular
b =
measured
with a C, axis
2.32l(3) between
were
atom method and refined
molecules
Pt-Cl
has been
a = 8.791(2),
Intensities
deviations
(with respect vibrational
discrete
principally
~phosphineccarbonionic
c
simply
are
group = 4.
by the heavy
2.335(3).
interactions,
(ato
space
solved
comprises
with bond leng?ths (in 1)
of c&-[PtC14(PEt3)21
p = 91.92(2)*. z
and the structure
= 0.053.
structure
monoclinic,
17.899(3)J(.
diffractometer g
and molecular
Cl<<
lengths)
and Cl
It is shown that differences
platinum(W)
complexes
are
not
in the bond lengths.
INTRODUCTION
The oxidative reactions
and reductive
that are homogeneously
the interconversion RhI or RB) R-
addition
No reprints
of square
and octahedral available
catalysed
planar
complexes
elimination by transition
complexes of higher
of lower oxidation
cycles metal
of several complexes
oxidation states
involve
states (such as III or PtIv). In
(Rh
398 recent years accurate planar
complexes,
especially
such as platinum(W) scopic
evidence
the tnns bonds
suggests
report
those of platinum(iI).
structural strengths
may be substantially
the crystal
provide
for platinum(R)
and platinum(W)
is spectro-
on the nature
to that of platinum(R)-l&and
bonds
complexes (as indicated
of &-[PtC&(PEtJd;
complexes
by the We now
the bond lengths
points of comparison
from
of
with resuks
the literature.
PtCI,(PEtJ,]
-,i-ere obtained with chlorine
by treatment
of&-[ptCl,-
followed
by recrystallisation
a = 8.791(2).
2 = 12.501(2).
dichloromethane-ether. Data
17.599(3) C-X-~,
ii,
I,
e = 91.92(2)‘.
F(000)
= 1112.
systematic
573.3,
radiation,
of h&l
for
A crystal
di&actometer
calculated
of size
&aphite a triclinic
from
on a Hilger
cell and accurate
the setting
angles
X=
and it was
space
g
groups2/c
91.13O.
Intensity
by an L‘ /2 6 step scan. two-fold
symmetry
found that the crystal
Preliminary
photographic
data were
= 0.70926_:]
2 = 7.638(2)
data for unique reflections After
the structure
-1,
on
e-t = 70.23
n-ith 2~6~
had been solved.
a re-examination
axis was
the needle
circle
in this assignment
[ .I (JIo-_K1)
h = 7.644(l).
prompted
needle
.
along
Y2SO four
ceR dimensions
of 12 reflections
(2).
$ = 85.92(2),
and Watts
monochromator)
crystal
to give a = 17.599(3).
high molecular
cm-l,
DC = 1.S4
@ f C, odd and & 0 1 for 1 odd.
O.&T x 0.36 x 0.18 mm u-as mounted
the diffractometer
collected
w = S1.S
2 =
Measurements
and used for data collection
had indicated
JIonoclinic,
U = 1965.9_i_3. Z = 1, Dm=2.17(flotation).
MO-Iipc
absences
Crystallorrraphic
were
states
in these two o_xidation states.
a nurmber of significant
of c&-[
C+&I,P,R,
axis
depend
there
for platinum(N)
and Pt-Cl
structure
in benzene-dichlo_romethane
Crystal
from
similar
Whilst
oxidation
I\;TA L
Crystals
from
of Pt-P different
and molecular
in this compiex
(X%3)2]
bond str’engths
information
for many square
but the higher
neglected,
in a way that is qualitatively
that the relative
E XPER’IME
has been obtained
have been comparatively
the available
bond le&hs)
information
that platinuxn@W-Ii,-
ligand
[l].
structural
the
of the unit cell.
in fact a face diagonal
25’
of the
399 monoclinic cell shown in the crystal data.
The intensity data u-as re-indexed on the
basis of the monoclinic cell using the matrix (0 Lore&z
-1
l/O
1
l/l
0
0).
and polarization corrections were applied and the data corrected for
absorption with the program ABSCOR[2].
Symmetry equivalent reflections were
averaged to give 1653 independent reflections with J_ >
30 0.
Structure Determination All non-hq-drogen atoms were kxated by heavy atom procedures with the molecule lying on the crystaIIo,mphic
two fold axis.
Least squares refinement =
with anisotropic temperature factors converged at & TABLZ
Pt CUl) CI(2) P(l) C(l) C(2) C(3) C(4) C(5) C(6) H(l1) H(12)
HCZU
H (22) H (23) H(31) H(32) HMU H (42) H (43) H(51) H(52) H(61) H(62) H (63)
Hydrogen atoms
1
FRA cTIOX4 L ATOMIk
Atom
0.058.
CO-ORDINATES
X
0 2-105(3) -816(4) 699(3) -584(14) -296(1S) 25S3(13) 3897(14) 7570 6) -729(19) -50208 -1726(14) -11 SO(19) -565(1 S) 769(19i 2750(13) 2666(13) 5091(14) 3718(14J 3532(14) 1515(16) 1220(16) -61’7(lS) -1458(19) -1222(19)
(x10”) WITH STANDARD
Y
1039.5(4)
1005(2) -356(2) 2264(2) 3395(S) 4153(11) 2804(S) 2077(12) 1720(10) 1352(13) 3847(19) 3086(S) 4724(11) 3713(1X) 4571(11) 2959(S) 3547(S) 2206(12) 2016(12) 1345(12) 1040(10) 2332(10) 91903) 2037(13) 8340 3)
DEVIATIOI’G
z
2500 3076(Z) 3311(2) 1588121 1495(7) 857(S) 1750(7) 1508(g) 648(6) 284(S) 2009(7) 1417(7) 956(S) 351(9) 80i (9) 2341(7) 1445(7) 1639(S) 910(S)
1769(S) 669(G) 296(6) -233(S) 189(S) 694(S)
400 were
introduced
fined as rigid methylene atom,
at Mealised
bodies
positions
with a common
hydrogen
atoms were
again with a common
at 3 0.053.
Scattering
Fo?, . from
3.
ref.
thermal
FinSi
ARD
are
1.
regular
P(l’),
Cl(2).
distances
octahedral and Cl(2’)
from
smaller angle
structure
and angles
above 0.060~
from
and is enhwged
hydrogen
atoms
obtained
2.4721 and the van der
from
(90.24
C(6’)
[H(6’3’)]
appears
given
+ 0.000025 were
taken
1, and anisotropic
Waals
scheme
to be free
for the atoms
lies between
(P) and 0.036_:
is given
some
and below
P(1’)
which
are
above
90’ due to H..
co-ordinates
some-xhat [;t] _ The
from
(2. SOi).
(177.84. because
atoms
RC12-
.H contacts
between
distances
atoms,
are
and some
the bond angles
compression
in -cis-[
of the hydrogen
P(l),
and Cl(2’);
Several
ligands.
contact distance
these tu-o chlorine
angle
in
by Pt.
found for c&-[PtC1,(PJIeJz]
to the corresponding
of
distortions
plane defined
(Cl).
and Cl(l)-Pt-CI(1’) from
3. and a diagram
and shows
P(1) and C1(2),
is evidellt
(86.59.
by nor-ma1 van der
in Table
A least-squares
from
the ideallised
of the l%Cl, moiety
Cl(Z)-Pt-Ci(2’t
are
of the triethylphosphine
between
Cl(2)
corrections
units separated
planarity
: simibr ..s
Ii . . . Cl,
(88.2’).
parameters
and dispersion
OF discrete
passes
(98.14
[96.2(4)4
compression
converged
2.
co-ordination.
than the deviations
methylene
for positional
and
carbon
Refinement
as 3 = 102/(l
has a C, axis of symmetry
the plane are
P(l)-pt-P(1’)
(PJIegJ
re-
factor,
empirically
with the numbering
The molecule
from
factor.
are given in Table *
in Table
composed
Eond lengths
contacts.
Figure
atoms
co-ordinates
given
temperature
were
on the corresponding
shift to error
u-as defined
groups
DISCUSSION
The crystab
the molecular
are
Methyl
isotropic to ride
temperature
for neutral
atomic
parameters
RESI_%TS
Wials
hydrogen
isotropic
scheme
factors
1 .OS A].
constrained
EL = 0.070 with a maximum
The weighting
of 0.08.
[d(C-HI
Cl(l)-Pt-Cl@‘)
The angle a hydrogen
Cl(l)-Pt-
atom on
@I.. . Cl distances
2.47 and
2.89-i). The length of the Pt-Cl(l) those
in trans-[PtCl,(PEtdJ
pyridinepIatinum(IV) from
bond trans
[2.332(5!
[mean
value
2.316(11)
that in [RCl,(C&,Nl,C$IJ[mean
* Structural
factor
tables
are available
to chlorine
[2.321(3)
&s
A] 151 and tetrachloro(pyridinium
value
from
A] [S],
and is not significantly
2.290(16)f\]
[7J.
similar
to
propylide) different
The bond lengths
in
the authors, (Continued
on p-403)
401 TABIX
2
ANISOTROPIC U&%
STAhQARD
Atom
PARAMETERS
Pt
341(3) 435(15) 65907) 431(13) 689(70) 853tSSI 499(59) 475(64) 782(81) 964(112)
a(2) P(l) C(1) C(2) C(3) C(4) C(5) C(G)
1,
probability
*2
DE~TIOIXS
A view
-f-
IN
Cl1
cm
Fig.
THERhtiL
* 2 + L’,g_2&.*2 + u&g
2u,g.&9*
(xl0’)
282 (3) 6140 9) 37OU 3)
594(4 856(21) 808(19)
342(13) 612(16) 427(.57) 669(68) 545(701 825(91) 423Es1 836(80) 723(85) 1 OSG(108) 571(68) 494(59) 763(68) 727(86)
of the molecular
_ The molecule
THE
FORM:
+ 2U2&ib*
exp[-2m*CT] WITH
PAREMHESIS
u33
%2
OF
i- 2U, &&a *g’
structure;
hzx a two fold uis
c 12
0 -2(11)
-7G(ll) 22(11) 145(51) 144(6-a -77(4G) 75(60) 4(58) 29(82)
thermal
ui
3
-35(2) -103(14) 80(14) -13(11) Gl(55) 116(731 79(55) -45(65) 17(55) -151(78)
ellipsoids
of symmetry.
enclose
‘23
0 98 (14) 92(12) 28 (10) 132(50) 201(64) 26153) 75 (77) -37(49)_ -251(74)
50$,‘&of
402 TABLE
3
SELECTED
ILNTERATOMIC
STA XDA RD
DISTANCES
(_:,
Ahi
AKGLES
(‘1
W7TH
DE VIA TIOSX
Bond lengths
Pt-Cl(l)
P(l)-C(5) C(l)-C(2) C(3) -C(4) ‘X5)-C(6)
2.321(3) 2.3%(3) 2.335(3) l.Sl3rll)
Pt-CI(2) 5%-P(l) P(l)-C(1)
1.816(11) 1.512(17) 1.536(17) 1.X2(19)
Bond angles P(l)-Pt-P(1’)
98.1(1)
R-P(1)-C(1)
113.4(4)
P(l)-Ft-CI(l)
93.8(l)
Ft-P(l)-C(3)
113.3(4)
P(l)-Pt-CI(l’) P(l)-Pt-CI(2’) Cl(l)-J?t-Cl@! Cl(l;-Pt-C1(2’) C1(2f-Ft-Cl(2’) P(l)-Pt-CI(2) c-(I)-Ft-Cl(1’)
87.6(l) 87. SW
Pt-P(l)-C(S) C(l)-P(l)-C(3)
114.7i-1) 106.8(6)
90.2(l) 88.20) 66.50) 172.90) 177.811)
C(l)-P(l)-cm C(3)-P(l)-C(5) P(l)-C(lt-C(2) P(l)-C(3)-C(4) Po)-C(5)-C(6)
19i.l(6) 103.5(G) 116.0(9) 115.1(9) 117.5(10)
TABLE
4
YEAS
BOXD
LENGTHS
(_%) IN cis
AXD
trans
ISOMERS
OF [PtC12(FXt-J.j
[14C~p=J):l
Configuration
Bond Pt-P(trans
to Cl)
-cis
2.“5wa
Ft-Cl(trans
to P)
-cis
2.361(s)
trans
2.314
trans
2.301m
pt-PW
to P)
Pt-Clkrans
a
ref.
12.
to CO
b this work .
c estimated
pt(IW
PtCrn
values
2.335(3)b 2.394(3)
c’
- see text.
.2.393(5) 2.332(s)
d
ref.
5.
d
A&m
403 the trans
P-Pt-P
moieties
of trana-[PtCl,(PEt$J
(Cl,C~~(~~~Ie)~(PEt~JC10~~rnean so the available are
results
not signifioantly
the Pt-Cl
lignnds
trans
to a carbene
2.415(4)
are
trans
manner: d
ionic ligands
2.362 trans
.
There
results
methyl
containing
(this work
two-dimensional bond lengths complexes.
value
obtained
Pt-Cl
moiety
(PAIeJJ
2.314(81
51, but the results
group.
increase the nature
The
and 2.315(4]
by 0.08i
i
distance and other
distance
complexes is estimated complexes
by 0.03A
@and.
Comparison
that there
are
was
isomers
of the
and [PtCII(PEtJJ were
obtained values for
depend
mainly
at 2.301(5) containing
from
of the
the results
related on the
.$ from
the
a trams Clfrom
the
[14] and trans.-[I%&of platinum(Ib
and the Pt-P not significantly
of bond lengths
states.
group.
accurate
from
in
for these
of 2.31415) _t can be inferred
, and that these increments
of the trans
More
found for trans-[PtBr,(PEtdJ
increase
distances
and piatinum(I0
and trans
(‘Ikblo 4) show that on oxidation
distances
to carban-
the Pt-Cl
(12,141
2,301(4)
to triethyl-
who showed
for trans-[RC12(PEt3)2]
in platinum(B)
Pt-Cl
For are:
tnns
that at least
for both &
[RCl#Et-JJ
[9].
ligands
to the methyl
can be estimated
- [lo]
and the R-P
the Pt-Cl
trans
of low precision.
the bond lengths
[16] _ The results
plstlnumQVl
complexes
for [PtCl$PEt3)] [la.
ligands
and
to tri-
in the h\-0 oxidation [l]
2.372(3)
m
1131 trans
for platinum(IVJ
have been determined
in trans-[PtClz(PEtJJ] since
indicating
et al.
5).
in a similar
lignnd
2.361(S)
between
is similar
of ‘J(Pt-C)
various
data and so are
of the trans
values
values
and platinum(W) and ref.
correlation
on
(this worlr),
vary
to various
[ll],
Both
with thevarious
and 2.393(j)
and 2.398(4)-2.4l5(-1)
to those of Clark
between
Bond lengths
ligand
influence
a good correlation
complexes
and ref.
lengths
to a carbanionic
complexes,
of a
Pt-P
similar,
depend si,tiicautly
to Cl (this work
(in A) traua
is a satisfactory
are analogous
complexes
trans
[12].
closely
relationship.
to triethylphosphine The
to a carbene
and platinum(lB
the mechanism
in &
(this work), 2.388(4)
distances
also
lengths &I A) associated
[a].
i
[5] and of [PtClEC-
in platinum(IV)
complexes
trans
l@nd
to chloride
Pt-Cl
the platinum(IW
nature
2.38-S(3)
A]
IS] are
of ligands
and 2.332(51 trans [S].
in&-[PtCl,(PEtJJ
platinum(B)
P&Cl
18. 5j, and 2.418(3)
to Cl [lo].
These
The
trans
platinum(JI)compl
ligands
ligand.
ligand
2.335(3)
phosphine
in platinum(IW
to a carbanionic
ethylphosphine
trans
on the nature
lengths
2.321(3)
2.388(4)]
that the bond lengths
dependent
of the trans
B
-_
su,qest
and the Pt-P
the nature
value
[2.393(5)
to
distances de_pendent on
in the square
planar
404 rhodium(I)
complex
corn&z
mhCl(PPhJ
B-mhCl,(PBuJ,
the Rh-Cl
platinum similarity
because
ordination
number
contrast
lengths
-[MC14(P31e$h)2] ordination
and 0.029(6)
[&I =. Re, aith
bonds
octahedral
for which
figuration,
a more
complexes
involves
Mason
results
et al __.
to provide
In the platinum
of the M-P
sense
a change of co-
thl?kchanges
there
in M-P and trans
is no variation
me),
N
in CO-
from
0.028(6)
;\I0
(Cs),
to
an&
of these
CI-pt-Cl
Pt-P
complexes,
detailed
analysis
removal
are involved
of electrons
in a graph
quantitative
appears
but the changes
at present.
to be
in the JI-
A number
The oxidation
of (ideallised)
in the oxidation
be a possibility
a more
on oxidation
of un-
of the
tzg symmetrya
of platinum(IQ
to platinum
be&u-een the results
for iridium-
of AI-P
Iength against
of error
in attempting
explanation
electron
con-
to extra_polate
of the bond length
changes
complexes. in Table
complexes.
mean wavenumber
for
d6
The results
to those found for platinum.
4 can be compared
A detailed
has been made for trimethylphosphlne
cm-l
complexes
x-[i\ICl,(PMe,Ph)~
bonds
[5] noted a discontinuity
The bond lengths
for
structure.
by 0.025(3)
for the platinum
precludes
so there would
parameters
involves
They found that on oxidation
state.
to Cl) shorten
(WJ and those for platinum(Iv),
+S cm1
the
to octahedral
who studied
OS, and Ir).
in the opposite
the da2 electrons
ALo,
[a
complexes
The lengthening
A @r).
are
certainties
to platinum(lV)
of Mason&&.
oxidation
Cl lengths
The
li,ds,
noted for the platinum
and M(ll.9
(trans
to that observed
their
to I? is
than that for the
d8 complexes
as a change of electronic
in the M(m)
analogous
0.
state
and the M-P bonds (trans to I?) lengthen by 0.047(6) (Re). 0.040 (OS
A(k),
whereas
oxidation
bond (trans
in the phosphorus
that the trends
p?.atinum(II)
with those
number
the M-Cl
0.037(6)
that in the higher
is less precise
of sq*uare planar
from
as well
somewhat
X-Cl
&I(W)
suggests
rhodiumcm)
_ The oxidation
ard
shows
of the variation
for ox&&ion
in the octahedral
longer and the Rh-P
to p) is 0.03i
of the results
complexes
[181
Although this comparison
complexes
may be general
with those
P(ObIe)J
bond (trans
longer.
0,065~
J [q
changes vibrations,
vibrations
trans
-9 cm-’ to Cl,
study of the platinum-llgandvibrations
analogues
on oxidation
with other_physicaL
of the complexes
from
for
R-Ci
and -9 cm-l
pl&inum(IL) vibrations for
P-Pt-P
in Table
4 [l
to platinum(lVl e
to 9.
vibrations.
Sj . are
-19 The
405
differences
in vibrational
(1W complexes
frequencies
were also studied.
between octahedral
and they appear to correlate
with the bond length changes found by Mason _et al. vibrational simply
frequencies
[S’j .
on oxidation of platinum(IIl
frequencies
valid method of estimating lJ(Pt-P)
relative
for trans.-[ PtCl,(PbIeJd
bond strengths, is
factor
2
platinum(X)
is 0.646 [19].
Since the coupling constants are related
orbitals
forming
ideallised
the I+P
complex,
of 0.664 smaller
corresponding
and the similar
assumptions
involved
complexes
consistent
and the implied
with the observed
platinum(R)
complexes
to be necessarily
are not inconsistent
of the
for the
Although there are
of the coupling for the -cis and
in the changes in the Pt-P bonds are
closely
the smaller
For
between the coupling constants
that bonds with a higher s-orbital
Although the s-components
are now shown to be associated
the Pt-P
than that for the
values of the factors
there is a fair correlation
component are also shorter.
theory,
coupling constant
changes in length of the IX-P bonds (Table 4).
and the I%-P bond lengths [21], which implies
hybridization
may not be a
to the s-characters
in the interpretation
similarity
of
factor for the -cis complexes
states of platinum [20].
constants [ZO]. it is now clear that the similar
not
comparison
bonds, a factor of 0.667 would be expected
dsp2 and d2sp3 hybridization
some significant
expected
are clearly
complexes
The n.m.r_
well
the changes in
to platinum0
in square planar and octahedral
and platinum
reasonably
However,
related to the bond length changes (Table 41. so the direct
vibrational
m
iridium(IlR
of the bonds are not
related to the values obtained from simple coupling constants for the platinum(W)
with relatively
with the possibility
lon,m Pt-P
bonds. and the results
that the correlation
lengths applies to both platinum0
complexes
and platinum(W)
between ‘J(Pt-P)
and
complexes.
A CK-NOWLEDGENEhTS
We thank Professor studentship
R. RIason for X-ray facilities
and S.R. C. for a
(to R-J.!.
REFERENCES
1.
H. C. Clark, 1973.
L.E.
hlanzer,
and J.E .H. Ward,
Canad. J. Chem.,
52 (1974)